Apex predators (also alpha predators, superpredators, or top-level predators) are predators that, as adults, are not normally preyed upon in the wild in significant parts of their ranges. Some can be superpredators in some environments but not in others (e.g., domestic cats). Some species can be the end of long food chains, where they have a crucial role in maintaining and determining the health of ecosystems, although some predators may be the end of a food chain having only three stages (grass→deer→wolf), but this is the bare minimum for inclusion. Some, like big cats, bears, hyenas, crocodiles, wolves and large dogs, some sharks, the Komodo dragon, and the orca are potential man-eaters, although most of them will avoid humans. Even those not dangerous to humans (e.g., owls) are formidable predators in their respective niches.

Ecological role

The range of different apex predators may cause some confusion, as some are much larger or differently adapted than others. A predator becomes an "apex predator" when the other species living alongside it cease to consider that animal as prey, or only attempt to attack it in the most dire of situations. For instance, although killer whales (orcas) occasionally attack and, even more rarely, feed upon great white sharks, both remain apex predators because such an occurrence is sufficiently rare for it to be considered a freak event. However, orcas frequently target leopard seals as prey, making seals a regular item on the menu, and thus not apex predators (even though orcas are their only consistent predator). Tigers/lions and crocodiles exemplify apex predators that occasionally interact violently with one another, but don't normally risk contact with prey that might kill or cripple them. Dogs might be vulnerable to larger and more powerful predators, but in many places they are the most powerful of all predators.

The same weapons that make superpredators so formidable hunters (claws, talons, teeth, power, strength) typically make them superb defenders of themselves. Even so small a predator as the electric eel that uses electrical charge to kill small fish and crustaceans as prey can give an unpleasant shock to such an animal as a caiman, jaguar, cougar, dog, giant otter, anaconda, egret, or human, causing the misguided predator to seek something less troublesome.

In addition, the status of an apex predator depends only on its surroundings, not its universal hunting ability. All species are highly attuned to their environment, and apex predators only more so. Outside of their normal context such a predator could easily become prey to unfamiliar species, like putting a Komodo dragon in the grasslands alongside lions and hyenas. A sea star, cone shell, octopus, or a sea anemone that might have predators elsewhere might be the arch-predator of some small tide pool.

Humans can be viewed as the "ultimate" apex predator if one applies the food-chain definition, as humans have largely removed themselves from being preyed upon in the wild, and have used technology (especially firearms) and even other animals (dogs, horses, and elephants) to subdue, evade, and/or kill most of the wild animals that pose a threat to themselves. Certain regions of the world, mostly wilderness, are still dangerous to humans in this respect. Predators such as lions, leopards, Nile crocodiles and saltwater crocodiles retain notoriety for being "man-eaters", as the humans they interact with possess negligible weapons in order to defend against attack. Still, by and far humans have surpassed the evolutionary limits of their bodies, resulting in safety from nearly all natural predators.